A multiday severe weather threat will ramp up this weekend in the Midwest and South and then spread toward the East Coast by Monday. Destructive straight-line winds, large hail and tornadoes are all potential hazards.

Wildfires in South Korea are being fueled by strong winds and are among the worst the nation has ever seen in terms of land burned. The fires have consumed more than 67 square miles, destroyed more than 200 structures and killed at least 24 people. The Korea Forest Service has raised the wildfire warning to the highest level for the entire country.

Fire conditions worsened Tuesday, leading to an expansion in uncontained fires in South Carolina as fires continued to burn in North Carolina as well. One fire, the Persimmon Ridge Fire in South Carolina, tripled in size as "extreme fire behavior" was reported.

As the name implies, these larger waves can sneak up on unsuspecting beachgoers since they randomly occur amid smaller waves at the same beach. Sometimes, sneaker waves can surge up to 150 feet onto a dry beach, knocking people down into dangerously cold Pacific waters.

Multiple people are killed each year due to falling trees during storms or other weather, but there is no good record of the exact number. Here's why it happens, and what you can do to stay safe.